Vehicle-spring.



W. I. & A. F. PINE. 'VEHICLE SPRING.

APPLICATION FILED APR. A23. I9I7 1,251,099. Patented Dee. 25, 1911ATTORNEYS PATENT OFFICE.

WILBER J. PINE, 0F OSHKOSH, WISCONSIN, AND ARTHUR F. PINE. 0F CASTLEROCK, GOLOIB'ADO.

Specification of Letters Patent.

VEHICLE-SPRING.

Application led April 23, 1917. Serial No. 164,005.

To all whom 'it may concern.' v

Be it known that we, WILBER J. PINE and ARTHUR F. PINE, citizens of theUnited States, residing at Oshkosh, county of Winnebago, and State oflVisconsin, and Castle Rock, county of Douglas, and State of Colorado,respectively, have invented new and useful Improvements inVehicle-Springs, of which the following is a specification.

Our invention relates to improvements in vehicle springs and methods offorming the same. The objects of our invention are to provide means forconstructing a vehicle spring composed of a series of flat superposedand contacting leaves, arranged in such relation to each other that thespring itself will be shock absorbing, some of the leaves. acting inopposition to the others when the spring is in normal no. load, (or inlight load), position, but all the leaves being arranged to act incooperation with each other tov resist heavy loads, shocks or rebounds.

In this manner We are enabled to provide a spring having more than theusual number of le-aves (if desired), the additional number of leavesserving.- to strengthen the spring for heavy loads, shocks and rebounds,and also serving toy increase, instead of diminishing, the fiexibilityof the spring when sub.- jected to light loads. Our invention also hasfor its, object the provision of means for imparting great strength andrigidity to the central portion of the spring.

Figure 1 is a side elevation of a vehicle spring, embodying ourinvention, with dotted lines indicating the normal exion of the uppersets of auxiliary leaves, also indicating` the position which the mainleaf tends. to assume when loaded.

Fig. 2 is a plan view of the central portion of one of the leaves.

Fig. 3 is a fragmentary view in longitudinal section, drawn to avertical plane through the central portion of the spring.

Fig. A is a cross sectional view, drawn to a plane through the center ofthe spring, and showing the clamping plates.

Fig. 5 isl a similar cross sectional View, showing a modified form ofconstruction.

Like parts are identified by the same reference characters throughoutthe several views.

In constructing our improved spring, we preferably provide each leafwith a central longitudinally extending corrugation. These corrugationsmay be formed so that the convex face of the corrugation will fit theconcaved or depressed face of the corrugation in the next succeedingleaf, this arrangement continuing from the bottom leaf to the top one.If desired, however, we may form a portion of the leaves withcorrugations bulged in one direction, and the remaining leaves withcorrugations bulged in the opposite direction. For example, in Fig. 5the corrugations of all the leaves are bulged upwardly, but in Fig. 4the corrugation of the main leaf A and each auxiliary leaf B, B and Bbelow the main leaf are bulged downwardly, as shown at C, whereas thecorrugations of the upper set of leaves D, D are bulged upwardly, asshown at C', thereby providing a central cavity which may, if desired,be filled with a core piece E.

In constructing our improved spring, we first form the main leaf,shaping it while hot to conform to the desired normal curvature. We thenfit the auxiliary leaf B to the main leaf while such auxiliary leaf issufficiently heated so. that it can be readily shaped to conform withthe curvature of the main leaf, whereby the auxiliary leaf will alsohave .the same curvature. The next auxiliary leaf B is then fitted tothe leaf B in a similar manner, and each successive leaf is similarlyfitted to the one preceding it in a like manner. This practice isfollowed as to all auxiliary leaves on convex side or below the mainleaf, the work being done in accordance with long established custom.

After shaping the auxiliary leaves below on convex side of the main leafto conform to the desired curvature established by the main leaf, weclamp all of these leaves together and subject the main leaf to load,the degree of load applied being substantially the normal load which thespring is designed to sustain. 'Ihat is to say, we subject the spring toa weight, or tension, equivalent to what might be called the normal loadwhich the spring is designed to support as a full load. This causes themain leaf to assume an ogee curve, substantially as indicated by dottedlines in Fig. l. We then apply the auxiliary leaf D, While heated., andshape it Patented 1360.25, 1917.

in conformity with the curvature of the upper surface of the main leaf,while subjected to said load. The succeeding leaf D is then similarlyapplied and shaped, while heated, to the leaf D, whereby these auxiliaryleaves D, D are caused to exert normal tension toward the line ofcurvature of the main leaf, when loaded.

It is not essential that the auxiliary leaves B, B, etc., should beassociated with, or clamped to the main leaf preparatory to the loadingof the main leaf and the shaping of the auxiliary leaves D, D', etc.,thereto while heated, as above explained.

,A It will be ordinarily sufficient to merely employ the loaded mainleaf to establish the desired normal curve of the leaves D and D,although, for more accurate fitting of the leaves D and D', theauxiliary leaves B, B', etc., may be assembled with the main leafpreparatory to applying the load. In this manner the auxiliary leaves,above the main leaf, have a normal curve which exactly corresponds withthat of the remainder of the spring when fully assembled and loaded.

The number of auxiliary leaves used, either above or below the mainleaf, is not material to this invention. But it is a fundamental featureof our invention that some of the auxiliary leaves conform in normalcurvature to the normal curvature of the main leaf, while other of theauxiliary leaves conform in normal curvature to the curvature of themain leaf, when loaded. The words normal curvature", as used in thisdescription, are employed to designate thc curvature which the leaftends to assume when free, or substantially unloaded. We preferablylocate those auxiliary leaves, whose normal curvature corresponds withthe normal curve of the main leaf, below the main leaf, whereas thoseleaves whose normal curvature corresponds with that of the main leaf,when loaded, are preferably located above the main leaf. Clamping clipsF may be employed to bind the extremities of the auxiliary leaves to themain leaf, although these are not essential. Clamping plates G and H mayalso be employed above and below the central portion of the spring, andmay be secured to the vehicle axle by stirrup-shaped clips or yokes I,of ordinary construction. Lubricating ducts J and K may also beprovided, but these are made the subject of a separate application,Serial'No. 122788, filed Sept. 29, 1916, which application also showsand describes the cor rugations and liller piece or core E, em-

ployed in the construction shown in Fig. 5.

We claim:

1. The method of making leaf springs, consisting, rst, in forming a bowshaped main leaf and two sets of auxiliary leaves; second, shaping oneset of auxiliary leaves in conformity to the normal curvature of themain leaf when not loaded; third, shaping the other set of auxiliaryleaves 1n conformity to the curvature of the main leaf when loaded, andfourth, assembling said auxiliary sets in position to normally act uponthe main leaf in opposition to each other.

2. The method of making leaf springs, consisting, rst, in forming a mainleaf and auxiliary leaves; second, heating and assembling some of theauxiliary leaves upon one side of the main leaf and shaping themprogressively upon the main leaf and upon each other successively inconformity with the normal curvature of the main leaf, and third,loading the main leaf, and heating and assembling other auxiliary leavesupon the opposite side of the main leaf, and shaping them progressivelyupon the main leaf and upon each other successively in conformity withthe curvature of the main leaf ,when loaded.

3. The method of making leaf springs, consisting in assembling two setsof auxiliary leaves upon a main leaf, with one set of auxiliary leaveshaving a normal curvature corresponding with the curve ofthe main leafwhen loaded, and the other set of auxiliary leaves having a normalcurvature corresponding with that of the main leaf when not loaded, andwith the springs of each set exerting tension in the direction of themain leaf.

4. A leaf spring, comprising the combination of a main leaf and two setsof auxiliary leaves arranged with those of one set on the opposite sideof the main leaf from those of the other set, all of said auxiliaryleaves having normal tension in the direction of the main leaf, theleaves of one set having a normal curvature corresponding with thenormal curvature of the main leaf, and the leaves of the other sethaving a normal curvature corresponding with the curvature of the mainleaf when loaded.

5. A leaf spring comprising the combination with a main leaf, a set ofauxiliary leaves, each having a normal curvature corresponding with thatof the main leaf, and another set of auxiliary leaves, each having anormal curvature corresponding with the curve of the main leaf whenloaded.

6. A leaf spring comprising the combination with a main leaf, a set ofauxiliary leaves, each having a normal curvature corresponding with thatof the main leaf, and another set of auxiliary leaves, each having anormal curvature corresponding with the curve of the main leaf whenloaded, the leaves of the respective auxiliary sets being arranged toexert normal tension upon the main leaf in opposite directions. l

7. A leaf spring including the combination of two sets of leavesarranged to exertl normal tension upon each other in oppositedirections, one set of leaves having a normal curvature correspondingsubstantially with that of the spring when un- In testimony whereof I axmy signature in the presence of two witnesses.

WILBER J. PINE.

loaded, and the other set of leaves having Witnesses: normal curvaturecorresponding with that J. W. MARTIN, of the spring when loaded, wherebythe SOL. COHAN.

leaves of said last mentioned set may be utilized to load the leaves ofthe other set, when the latter are not otherwise loaded, and whereby allthe leaves may ooperate in 'supporting full loads and in resistingrebounds.

In testimony whereof I aiix my signature in the presence of twowitnesses.

ARTHUR yF. PINE. Witnesses:

GERTRUDE KOORMAN, J. J. CAMPBELL.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. C.

